In recent years, various light-emitting devices in which plural solid-state light-emitting elements such as light-emitting diodes (LEDs) are mounted on a substrate for use as a light source have come into practical use. Such light-emitting devices are widely used, for example, as a matrix display device in which a matrix of plural LEDs emits light selectively to display characters or images, a backlight for a liquid crystal panel of a liquid crystal display device, or the like.
As the related art disclosed in one official gazette, there is one in which RGB LED chips each having a lens correspondingly provided thereon are disposed in proximity to corner portions of an equilateral triangle, respectively, in order to achieve a high-density array and, a light emitting display surface with high brightness and clearness (refer to Patent Document 1, for example).
Also, in the art disclosed in another official gazette, in order to suppress unevenness of color of illuminating light emitted from an end of a lighting unit or from between adjacent lighting units, a light source having the same luminescent color as that obtained by the mixing of light from light sources possessed by the lighting unit is disposed at the end of the light source or between the adjacent lighting units (refer to Patent Document 2, for example).
In addition, in the art disclosed in still another official gazette, in order to produce an array of light-emitting elements that achieves a narrow angle of divergence of a beam of light emitted from the light-emitting element and also that does not allow occurrence of flare light, the following relationship is established:0.5≦(P−D)/(D/2)≦1.5,where P denotes an array pitch of the array of the light-emitting elements, and D denotes a diameter of a microlens (refer to Patent Document 3, for example).
Patent Document 1: Japanese Patent Application Laid Open Publication No. 10-12926
Patent Document 2: Japanese Patent Application Laid Open Publication No. 2005-243347
Patent Document 3: Japanese Patent Application Laid
Open Publication No. 2005-175417